How to play : Use an ordinary dark colored crayon or marker to draw a line on a white piece of paper. Turn on switch on the button of the car. Place car on top of the drawn line. The car will run on the line automatically. If the line finished, the vehicle will continue in the direction followed from the previous line. If the line is too thin, the vehicle may stray off the line, please make the line thicker ( the line should be a quarter inch thickness ) Feature : This is a novelty inductive tank, follows the line like magic. If you place the Inductive Tank Toy somewhere else it would run in circles only until it finds the line. The Children"'"s Tank Toy has an optical sensor that reads the black line drawn on a white piece of paper. The tank powered by 4 x AG 13 button cell. Turn on the power switch and the Magic Tank Toy can move atomatically. The line: not under 4mm, not overrun 10mm, non sharp-angled line. Perfect gift for your little child. Package : 1 x tank or car 1 x Magic pen 1 x Instruction manual 1 x White paper with black lines